Cummins Diesel Forum banner

Leaking Lift Pump?

12K views 8 replies 6 participants last post by  illflem 
#1 ·
There is fuel dripping off of my lift pump. I've read the tech and beginner threads and Mad Mike's thread. There is no fuel oil on the outside of fuel filter or on the fuel return line. No fuel is running down the block and none appears to be dripping onto the lift pump. What else should I do before deciding to replace the lift pump.

Thanks for such a great forum.
MM
 
#3 ·
haha i swear bill knows more neat chit than anyone i have ever known mechanically. i was just gonna say there are two gaskets on the lift pump....i just replaced mine about a month ago. im guessing one could go bad...so you could, if you wanted to, just order the gaskets and replace them...so long as the pump hasnt warped or got a small crack that is causing the leak
 
#4 ·
The gaskets are for oil, not fuel. Re-read Joe Gs article on fuel systems. It sounds like the o-ring on the manual plunger has failed. Some NAPA stores have assortments where you can find one that fits.
 
#6 ·
thanks for correcting me games. that slipped even my thought when i replied. so yea go with what games said those gaskets would only leak oil unless something else catastrophic had happened.
 
#8 ·
Truck shuts off while cruising in 5th gear!!

Hello,

I just purchased a 1995 F800 5.9 Cummins truck. The truck takes about 2 mins to start when standing on the accelerator. Once idling, the truck will stay on forever. When I start driving it, it shuts off in around 5th or 6th gear when cruising. The brake booster doesn't work, so this thing is literally an unguided missile when it shuts off. I rigged a boat gas can complete with fuel line and primer pump, directly to the intake of the truck's fuel primer and it does the same thing. Always taking a while to start back up when standing on the accel pedal. Should the truck's fuel primer get hard after pumping it? This one doesn't. The truck is located and hour and a half away from me, so it's not easy to find time to work on her. Any help would be appreciated.
 
#9 ·
Hello,

I just purchased a 1995 F800 5.9 Cummins truck. The truck takes about 2 mins to start when standing on the accelerator. Once idling, the truck will stay on forever. When I start driving it, it shuts off in around 5th or 6th gear when cruising. The brake booster doesn't work, so this thing is literally an unguided missile when it shuts off. I rigged a boat gas can complete with fuel line and primer pump, directly to the intake of the truck's fuel primer and it does the same thing. Always taking a while to start back up when standing on the accel pedal. Should the truck's fuel primer get hard after pumping it? This one doesn't. The truck is located and hour and a half away from me, so it's not easy to find time to work on her. Any help would be appreciated.
I started a new thread so you'll get better response.
Find it here> http://www.cumminsforum.com/forum/9...-off-while-cruising-5th-gear.html#post3653865
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top